Molding machine with compensating pad assembly



United States Patent Edwin C. Medill North East, Pennsylvania 701,382

Jan. 29, 1968 Nov. 10, 1970 'laccone Corporation North East, Pennsylvania a corporation of Pennsylvania Inventor Appl. No. Filed Patented Assignee MOLDING MACHINE WITH CQMPENSATING PAD ASSEMBLY 3 Claims, 3 Drawing Figs.

0.8. CI 164/170, 92/96 Int. Cl B22c 15/08 Field of Search 164/ l 70, 171; 249/65; 92/96, 98, 99, 52, 64

[56] References Cited UNITED STATES PATENTS 2,367,852 l/l945 Eaton 92/52 3,134,148 5/1964 Taccone..... 164/170 3,209,414 10/1965 Taccone 164/171 Primary Examiner-Robert D. Baldwin Attorney-Charles L. Lovercheck ABSTRACT: Apparatus is made up of a squeeze cylinder, piston, diaphragm, and associated equipment on a molding machine. The molding machine has provision for supporting a flask. The piston has a cavity facing the flask, and the diaphragm is supported over the cavity and attached to it by a squeeze frame. A supply of compressed gas is connected to the space in the cylinder behind the piston. A passage for gas is provided through the piston to the cavity behind the diaphragm.

Patentd Nov. 10,1970 3,538,979

Sheet L of 2 jam EDMN C, MEDLL BY M INVE R.

INVENTOR Bow/Iv c. MED/LL.

BY M K/ M -MOLDING MACHINE WITH COMPENSATING PAD t I ASSEMBLY v r 30 will be clamped tothe member 18 and hold the diaphragm Thus, when thecompression cylinder movesaflask toward the head, the pad or diaphragm first engages the sandin the flask, and as the squeeze cylinder moves on toward the head, the compensating head can'be forced into the flask and the compression cylinder is thereby forced toward the head, thus compressing the air trapped in the-cavity in the compensating padassembly and in the compression cylinder.

lnthissystem of molding, air is introduced into the air chamber; this blows the diaphragm against the sand in the invention eliminates the lack of pressure on the areas around bars and corners. The present invention also permits the use of deeper upsets if required.

It is, accordingly. an object of the invention to provide an improved molding machine.

'Another object of the'invention is to provide a diaphragm molding machine wherein the diaphragm formsa closure for a cavity in a member attached to a piston and the piston is slidably, received in thecylinder. The space in the cylinder behind the piston is connected in fluid "flow relation with the cavity closed by the diaphragm.

With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawings and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.

lnthedrawings: 1 FIG. 1 is a longitudinal.cross-sectional schematic view of a filled and head ready for a molding stroke; a

FIG. 2 is a view similar to FIG. 1, showing a machine according to the invention at the beginning of a molding stroke;

and a FIG. 3 is a view similar to FIGS. 1 and 2 of the machine in an advanced part ota molding stroke. 1

Now with more particular'reference to the drawings, the drawings show amolding machine having a pattern plate supported on the piston rod of a squeeze cylinder 12. A patrigidly against shoulder 31 on member 19.

Air may be introduced into the head by valve 21, which may be a suitable four-way valve having an inlet and an outlet 26. A'suitable actuating member canbe provided by the valve 25 that is familiar to those skilled in the art, so that air may be introduced into the cavity 22 or exhausted therefrom at the will of the operator. The piston 17 has passages 33 connecting the space 23 in cylinder 18 with cavity 22.

The air may be introduced at a pressure selected by the person using the machine for the particular condition of molding that prevailsThe pressure could be, for example, in the range of 1,500 pounds per square inch.

- Furthermore, the air could be putinto the head under pressure when the head was in the position shown in FIG. 2, for example, and the valve 2! closed, so that when the piston 17 a continued on into the cylinder 18 the air therein was compressed to a much higher pressure and therefore a much greater unitpressure is exerted on the sand by diaphragm 22.

The frame -will pack the sand firmly in the area adjacent the inside of thcflask and the diaphragm 20 will compress the sand around the pattern with a molding action similar to the molding action in US. Pat. No. 3,l34,l48.

"moldingzmachine according to the invention with the flask around the pattern 11. The sand would normally be of the type generally used in greensand molding.

The head 16 will normallybe fixed to the machine and the compression cylinder 18 fixed to the head. The compression piston 19 has the piston rings'24 which will be of a suitable type and is slidably received in'the compression cylinder. The

' compensating pad assembly 19 is fixed to the compression piston .17, and the member 19 will have a cavity 22 therein opening toward the sand in the flask. The cavity 22 is closed by the diaphragm or pad 20. The pad 20 will be of a flexible relatively thick type, .which'may be in the order of one-half inch or greater in thickness. The frame 20 will attach the pad to the member 19 around the periphery of the opening. Frame When the mold is completed, the head can be lifted to the position shown in FIG. 1, anti the air pressure removed from the chamberfl'hus. the diaphragm 20 would be drawn upward into the head in the position shown in H0. l.

The foregoing specification sets 'forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention'which is to be understood is broadly nove as is commensurate with the appended claims.

1 claim: 7

1. A molding machine comprising a head and a squeeze cylinder with a movable piston rod:

a pattern'plate supported on said piston rod;

said pattern plate being adapted to support a pattern;

a flask on said pattern plate;

a compensating pad assembly;

said pad assembly comprising a member adapted. to fit into said member having a cavity facing said flask;

a compensating cylinder fixed to said head;

a compensating piston slidably received in said cylinder;

said member being fixed to said compensating piston;

a flexible pad' fixed to said member and forming a closed cavity in said member;

and means fixing said pad to said member;

means adapted to supply and maintain gas under pressure to said compensating cylinder;

- member; said pad being adapted to compress sand in said flask when a force is applied to raise said piston rod whereby said gas is compressed in said compensating cylinder and in said cavity; and means adapted to exhaust gas from said compensating cylinder to draw said pad and said compensating piston upward'toward said head. 2. The machine recited in claim 1 wherein: a rigid open frame is fixed to said member around the outer periphery of said pad, clamping said pad to said member; and said frame fitting loosely into said flask. 3. The machine recited in claim 1 wherein means is supported on said head for holding a fixed amount of air in said cavity and in said cylinder. 

